Muffler structure with baffle means



April 17, 1962 G. A. LYON MUFFLER STRUCTURE WITH BAFFLE MEANS 3Sheets-Sheet 1 Filed March 24, 1958 ZZTVEZ'YZUF I Ggorye fl/erf LyonApril 17, 1962.

3 Sheets-Sheet 2 Filed March 24, 1958 hZ EHZUF Georye fl/ber/ Lyon fig aa I E/[575.

A ril 17, 1962 G. A. LYON 3,029,896

MUFFLER STRUCTURE WITH BAFFLE MEANS Filed March 24, 1958 3 Sheets-Sheet3 United States PatentO 3 029 896 MUFFLER STRUCTURE WITH BAFFLE MEANSGeorge Albert Lyon, Detroit, Mich., assignor to Lyon Incorporated,Detroit, Mich., a corporation of Delaware 7 Filed Mar. 24, 1958, Ser.No. 723,391 10 Claims. '(Cl. 181-57) Among the problems encountered arethe increasing need for more elficient muflling due to increasingdensity of populations and rising vehicle congestion, while at the sametime compression ratios and power of the engines has been increased. Thecurrent trend toward lower chassis and more complex bracing and framestructure further accentuates the problem. For improved power, the motorfuels are provided with additives which increase the corrosive effectsof exhaust residues in the presence of moisture especially where onlyshort runs are made so that condensate can accumulate because theexhaust system does not heat sulficiently to dry out.

The principal direction muffler designs have more recently taken istoward increasingly complex reverse flow types of muffler structures ofconsiderable length and transverse dimensions and involving somany pantsand so much material as to encourage the use of the most inexpensivematerial, generally sofit, untreated cold rolled steel, highlysusceptible to corrosion and thus early failure of the mufilers. I

It is, accordingly, an important object of the present invention toprovide improvements in mufiler structures adapting the same to be madein relatively small sizes but with unusually large sound damping,mufiling capacity.

Another object of the invention is to provide an improved mufilerstructure lending itself readily to simple construction and enablingsubstantial standardization of various pants to reduce the number ofmanufacturing operations.

A further object of the invention is to provide an improved mufilerstructure which may be selectively provided in various mufilingcapacities by the addition or subtraction of substantially standardizedcomponents in effecting assembly for various known requirements.

Still another object of the invention is to provide an improved mufilerstructure affording "a highly eflicient flow pattern minimizingaccumulations of condensate or corrosive residues within the muffler.

Yet another object of the invention is to provide an improved selfcleaning mufiler construction.

It is also an object of the invention to provide improved mufflerstructure which because of economical construction encourages the use ofhigher grade, more corrosion resistant materials.

A yet further object of the invention is to provide an "ice FIGURE 2 isa sectional elevational view taken substantially on the line II- II ofFIGURE 1;

FIGURE 3 is an end elevational view of a slightly modified form of themuffler;

FIGURE 4 is aside elevational view, partially in longitudinal section ofa modified form of the mufi ler;

FIGURE 5 is a sectional elevationalview taken substantially on the lineV'V of FIGURE 4;

FIGURE 6 is an exploded assembly view of the mufiler of FIGURES 4 and 5;

FIGURE 7 is a side elevational view, partially in longitudinal sectionof a further modification of the mufiier; and

FIGURE 8 is a top plan view of one of the casingbaffle sections of themufiler of FIGURE 7.

According to'the present invention, mufiling of pressurized flowinggases and especially such as produced by internal combustion engines isaccomplished by repeatedly breaking or sub-dividing the gas stream intoa large number of small more or less jet streams directed into headoncollision with one another in restricted chamber space under slight backpressure and then controlled onward movement. Especially where the gasstream is impelled with explosive, pulsating, percussive force, thehead-on impingement of the gas stream subdivisions has a beneficialimpulse cancelling, neutralizing effect until such a low pitch isattained as to be below an objectionable noise level, attainingsubstantial imperceptibility within the usual hearing range. Inaccomplishing this, the gases are conveyed in one general direction awayfrom the source without any necessity for reversal of movement improvedmuffler construction having novel cooling axially of the flow path, anydeviations from a continuous axial flow being across the general flowaxis and of lim-' .ited extent and purposeful effect.

In one form of the invention as shown in FIGURES l and 2, the inventionis embodied in a muffler unit 10 of suitable length and diameter andproviding a housing having therein a tortuous, step-by-step forwardlyadvancing, sound muflling flow path for the gas stream. In the presentinstance the mufller 10 comprises a telescopically internested series ofindividual elements enabling ready variability as to muflier length andsound damping capacity to meet various practical requirements and forthis purpose comprises a tubular end member 11, a series of muflliug baille members 12, a terminal b afile member 13 and associated therewithan end closure member 14.

In the present instance, the end member 11 includes a central inletprojection 15 adapted to be connected to an exhaust duct from the engineof a vehicle or other internal combustion engine. The inlet projection15 is of substantially smaller diameter than the principal diameter ofthe end cap member 11, and a flaring shoulder 17, preferably corrugatedfor strength connects the inlet with the tubular body of the member 11.

Each of the baflle member sections 12 is preferably of substantially cupshape and of substantially the same diameter as the diameter of the endmember 11 which is provided with an enlarged diameter portion 18adjacent to its free end internally dimensioned to substantially theoutside diameter of the baffle members 12 so that the first in theseries of baille members can be telescopically nested into the enlargeddiameter portion 18 which is provided at juncture with the main tubularbody of the member 11 with an offsetting stop shoulder 19 against whichthe shoulder of the bafile member bottoms in assembly to determine thecoaxial, operative relationship to the end member 11. Each of the bafilemembers 12, in turn, is provided in the axial wall thereof with asimilar larger diameter portion 20 provided with an offsetting junctureshoulder 21. against which the next of the bafile members 12 in theseries bottoms in telescopically nested assembled relation with theupstream companion baflle member. In

3 the assembled generally stacked, telescopically internestedrelationship, the baffle members and the end member are preferablyfixedly secured together as by means of welding or other suitablesecuring means to prevent separation under operating conditions. I

As a cooling expedient, the free end portions of the end member 11 andthe baffie members 12 are preferably of an enlarged heat transfer,shield skirt form as identified at 22 in each instance connected to theenlarged diameter assembly seat portionlS and 2-0, respectively, by aflaring forwardly and radially outwardly angled shoulder 23, while anannular out turned reinforcing and riffle bead terminal 24 provides afinishing edge for the free extremity of the skirt. Through thisarrangement, improved heat transfer to the slip stream air is attainedwhile the substantial dead air spaces in the chambers afforded betweenthe skirts 22 and the adjacent bafile walls have an insulating effectagainst undue heat radiation, especially where the mufller is mountedunder a metal floor deck of a vehicle.

For sound muffling control, each of the baflie members 12 is providedwith a baflle wall portion 25 which is disposed in completely blockingrelation across the inside of the chamber within the composite housingafforded by the assembly. Means are provided on each of the baffle walls25 for dividing the exhaust gas stream into a plurality of uniformseries of air streams or jets directed into sound damping, head-onimpingement. To this end, the baffle wall 25 in each instance includesone or more, in the present instance shown as two, corrugation-likeaxially rearwardly projecting continuous annular hollow rib formations27 each of which provides a groove chamher opening forwardly therefrom.In the opposing genthe directional flow arrows at the right-hand end ofFIG- URE 1 wherein it will be seen that the exhaust gas stream enteringthe muffler through the inlet 15 tends to expand laterally toward theperimeter of the chamber provided between the end member shoulder wall17 and the margin of the first of the baflle walls 25 and then issubdivided and flows into the opposing series of orifices 28 in thebaffle ribs 27. The aggregate flow area afforded by the orifices 28 issuch as to provide only slight pressure drop and thus only slight backpressure on the exhaust stream.

After the initial head-on jet collision reaction and thus substantialsound mufiling, the exhaust gases move forwardly from the baflle ribgroove chambers under controlled, muffling conditions, herein effectedby an auxiliary baffle disk 29 secured to the forward side of the marginof the baflle wall 25 and sloping forwardly and inwardly toward the axisof the muffler in diverging relation to the baflle Wall 2-5 and inpredetermined spaced relation to the mouth of the respective baffle ribgroove chambers so as to direct exhaust gas flow therefrom toward acentral opening 30 in the auxiliary baille. As a result, the exhaustgases issue from the opening 30 into the limited chamber space betweenthe adjacent baffles 12 in a more or less swirling stream having adesirable mufiiing effect as the gases move on to become againsub-divided by the series of orifices '28 in the next suceeding battleand repeat the mufiling cycle. As the cycle is repeated again I trol,collision-jet batfle members 12 in a manner to facili- 1 tate not onlyinitial assembly, but securement in the muffler unit. To this end, eachof the auxiliary or secondary mufiier members 29* is provided with aperipheral generally axially extending flange 31 dimensioned forslidable, preferably press fit engagement within the tubular wall of theassociated balfle member 12, and with the corner junctures of theflanges 3 1 with the body portions of the bafile members 29 nested orbottomed in the reentrant corner defined between the tubular and bafllewalls of the baffle member 12. This properly orients the secondarybaflie members 29 within the bafile members 12, and also I disposes theflanges 31 of the secondary baflle menbers substantially coextensivewith the offset encompassing seatportions 20 of the member into whicheach of the respective baflie members 12 is telescopically engaged sothat, especially where welding is employed to secure the memberstogether, all three internested components in each instance can be andare secured together in a single welding operation.

By the particular construction of the bafile wall portions of the bafllemembers 12, suflicient limited axial resilient flexing or yielding ispermitted to avoid undue strain in the event of back fire of the engine.Nevertheless, although the concentric jet orifice ribs 27 enhance theresilience of the baflie walls they also assure lack of resonantresponse to the exhaust gas pulsations but actually act as sounddampers. Not only resistance to deformation but also further enhancedsound deadening is accomplished by having central concave convexportions 32 on the respective baflie wall portions of the baflle members12.

At the exit end of the muffler unit 10, the terminal baflle member 13which in other respectsmay be substantially the same as the'bafflemembers 12 is formed in this instance with a straight tubular freeterminal end portion within which an axially extending marginal flange33' on the end closure member 14 is telescopically en gaged and secured.As shown, the end closure member is in the form of a generallyfunnel-shaped structure tapercollision, swirling stages of mufllertreatment, gradually.

freer flow, slow down is effected. Although in the relatively cold stateof the muflier and slow speed operation of the engine there may besubstantial cooling of the exhaust gases from the inlet to the outletends of the muffler and thus inherent slow down due to contraction ofthe gases by cooling, in the high speed operation of the engine andafter the mufller has become heated to the point where contraction ofthe gases is only a minor factor, a gradual increase in the aggregatecrosssectional flow area of the jet producing apertures 28 in thesuccessive baifle plates affords the gradual reduction in pressure dropand thus slow down of the gases and freer flow as the sound producingvibrations and impulses of the gases are gradually dissipated *and thenoise level curve moves nearer to the flat sound free condition.Increase in the aggregate flow area may be accomplished by an increasingnumber of the same size holes, but is shown as conveniently resultingfrom gradually larger size holes of the, same number in each series ofthe jet producing apertures 28 in each successive battle p ate.

Although the cross-sectional form of the muffler 10 in FIGURES 1 and 2has been shown as circular, as may generally be permitted in view of thesmall size of the muffler, where head room or other conditions require,the mufiler may be of the oval shape of the muffler 35 in FIGURE 3 withrespect to cross-section, but in other respects may be substantially thesame as the muffler 10 or the other forms of the mutfler to behereinafter described. s a

In FIGURES 4. 5 and 6 a modified mufller structure 37 is shown which ingeneral respects is similar to the mufiler 10. To this end the mufiler37 includes a forward end tubular section 38 having an inlet extension38a and a flaring shouldered structure leading to a tubular wall thattelescopically receives .therein and is suitably secured fixedly about acomplementary diameter tubular, generally cup shaped first vbaffiemember 39 in a series of such baffle members which in turn hastelescopically fitted there-into the next succeeding baffle member 39,and so on throughout a substantialseries of the baffle members dependingon the number required for any given preference 'or muffling orsilencing condition. Each of the muffler members 39 has intermediatelyin the axial tubular wall thereof a shoulder 40 which faces generallyaxially rearwardly and receives in locating relation the edge of themember .telescoped thereabout on its outer side and also oralternatively the next succeeding telescoped inner-end shoulder of theassociated bafile member. At its exhaust end, the muffler 37 includes anexhaust closure nozzle member 41 having an axially 'extending marginalflange .42 secured telescopically within the last in the series of thebaffle members 39 and of gen erally tapered nozzle structure with atubular exhaust extension 43.

, Each of the baffle members 39 is provided with a bathe Wall 44 thatextends in closing relation across thechamber defined within the muffler37 and has adjacent its margin a rearwardly projecting continuous rib 45defining a forwardly opening chamber and having in the opposed sidewalls thereof opposing circumferential series of jet producing apertures47. Thereby the exhaust gases advancing forwardly through the mufller 37are divided'adjacent to the perimeter of the baflle member 39 in eachinstance into a large number of opposing, colliding jets within thechamber defined by the respective gas sub-dividing, collision jetproducing rib 45. Attached to a rearwardly convex and forwardly concavecentral wall portion 48 of the baffle member is a control auxiliarybaffle plate 49 which may be of complementary concave convex form andwith the margin thereof extending generally radially outwardly andaxially forwardly across the mouth of the jet rib chamber, affording agap with the radially outer margin defining the chamber mouth to divertthe gases under controlled conditions toward the perimeter of thechamber defined between the forward side of the baffle wall 44 and thenext forward bafile wall44 In so issuing the exhaust gases assume agenerally whirling action and are then compelled to move generallyradially inwardly toward the center of the mufiler and are againsub-divided into a series of jets by the jet aperture orifices 47 of thenext succeeding bafile member for repeated head-on jet collision andthus impulse, sound wave cancelling reaction. Each succeeding series oforifices 47 may be of at least slightly greater aggregatecross-sectional flow area to accomplish gradually slower and freermovement of the gases as the sound producing factors in the gases aregradually eliminated or at least subdued.

In FIGURE 6 is shown how assembly is adapted to be effected bytelescopic series assembly insertion of one baffle member into theother.

In the modification of FIGURES 7 and 8, a somewhat simpler, highlyeffective muffler 50 is disclosed including an inlet end closure portion51, a series of muffling baffles 52 and an end closure funnel nozzlemember 53. Similarly as in the other forms of the muffler disclosed, theinlet'member 51 has an inlet opening extension 54 from which a flaringshoulder leads to the full diameter tubular wall of the inlet membertelescopically engaged about the tubular wall of the first of the bafllemembers 52 in the series which is provided intermediately with an offsetshoulder 55 by which the relative axial disposition of the members isdetermined in assembly.

In this instance each of the baffle members 52 has a baffle wall 57provided with a continuous forwardly projecting rib 58 having slightlydivergent axial walls provided with multiple series of jet orificeapertures 59 in each instance, and with the respective series in eachwall matching and opposing one another in the opposite walls so as toproduce respective jets in head-on collision within the chamber definedby the orifice rib 58. By the plurality of axially progressive seriesherein shown as three in each wall of the orifice rib not only is theexhaust stream sub-divided into opposing jets which collide head-on inthe rib chamber but upon spreading out after collision the jetscommingle in a generally turbulent relationship which further acts tosubdue sound producing pulsations.

In the mufiler 50, the jet ribs of the succeeding bafiles 52 aredisposed with respect t-othe immediately preceding bafile wall 57 tocontrol, and divide the exhaust gases issuing from the mouth of the ribchamber .of the immediately preceding bafile wall into divergent streamportions flowing into the between baffie chamber for resubdivision intojets within the next succeeding baflle rib for the next stage of headronjet collision sound impulse or wave reduction and mufiling. Thiseliminates the need for a separate or secondary control bafflestructure. By having the respective baffie members coaxially located inpredetermined axial disposition by means of the shoulders 55, locationof the crown or ridge portions of the respective succeeding jet bafileridges 58 in proper controlling relation to the mouths of the respectiverib chambers is facilitated.

Ifpreferred, of course, the jet orifices 59 in the respective succeedingbatlles may be of progressively increasing aggregate cross-sectionalflow area, but as shown all of vthe orifices are of the same size inview of the fact that there are a substantially greater number of thejet orifices in each of the bafile ribs to begin with.

Inasmuch as the central portion of the baffle wall 57 in each instanceis of substantial diameter, it has been found advantageous to have, thesame of rearwardly concave and forwardly convex shape as shown, therebycffectively avoiding any diaphragm resonance and any tendency to buckleunder back fire since the direction of concavity is in the direction ofmovement of any sudden surge of exhaust or products of combustion gasesthat may pass through or originate in the mufiler in a back fire.Nevertheless, there is a desirable resilient cushioning deflectabilityin the bafile walls 57.

In order to provide for efficient blowing through of condensate, soot,lead or other residues or other contaminants, the marginal portions ofthe bafile walls 57 radially outwardly from the jet ribs 58 arepreferably provided with blow through holes 60 in suitable series, ofsmall size and spaced preferably circumferentially a suitable distance,although if it is known which portion of the muffler will be down in theoperating system, one or more of the blow holes 60 may be provided onlyon the down side of the baffle wall. Since the blow through holes 60 Aare of substantially smaller aggregate cross-sectional flow area in eachinstance than the cross-sectional flow area afforded by the collisionjets 59, only a minor proportion of the exhaust gases will blowtherethrough and will come into turbulent interference with the gasesthat issue from the respective associated jet ridge chamber in eachinstance, so that there is little likelihood of any of the ex- I nozzle53 has an axially extending marginal flange 61 which is telescopicallysecured within the end of the endfor forming the desired shapes.

most of the baffles 52 and is provided with a generally funnel-shapedstructure terminating in a tubular exhaust nozzle extension 62 which ifpreferred may, as shown, be slightly smaller diameter than the inlet 54for the purpose of minimizing back fire.

Any of the mufflers may be made from suitable sheet material such asstainless steel, aluminized steel, aluminum alloy, or suitable heat andcorrosion resistant moldable plastic material having a satisfactory costfactor. Sheet metal has presently the advantage of economical base costand mass production manufacturing techniques In view of the ruggedconstruction of the several components, fairly thin sheet material maybe used. By the use of higher grade materials greatly increased mufllerlife can be attained.

' In all forms of the invention, the high muflling efficiency attainedenables the use of small sizes of the mufflers with nevertheless highefficiency rating. Because of the sectional assembly of the baffles,mufllers of vary- .ing capacity can easily be assembled to suit variousrequirements. For example, in association with a vehicle engine that hasa dual exhaust system, two mufflers of medium size may be used in eachof the dual portions of the exhaust system. On the other hand ifpreferred, a plurality of mufllers and silencers all made up fromappropriate numbers of mufiler baflle sections may be used, thesilencers having smaller numbers of sections than the mufller units. Inother words, a high degree of flexibility for desired results isattainable by virtue of the telescopically related sectionalconstruction of the mufilers.

It will be understood that modifications and variations may be effectedwithout departing from the scope of the novel concepts of the presentinvention.

I claim as my invention:

1. In a mufller structure, means defining a muflle chamber havinganinletand an outlet, a control baflle across the mufile chamber havingformed therein and projecting toward the inlet a jet producing hollowgrooved rib having opposed generally axially extending substantiallyparallel adjacently spaced wall portions with opposed orifices thereinthrough which fluid to be mufiled coming from the inlet must pass in theform of opposed jets to collide head-on within the groove defined by therib, said rib groove opening toward the outlet, and a fluid controllingbaffle member disposed at the mouth of said rib groove 'and'operative todivert the fluid issuing from said rib groove laterally within themuflie chamber.

2. In a mufiler structure, means defining a muflle chamber having aninlet and an outlet, a control baffle across'the muflle chamber havingformed therein and projecting toward the inlet a jet producing hollowgrooved "rib having opposed generally axially extending substantiallyparallel adjacently spaced wall portions with opposed orifices thereinthrough which fluid to be mufiled coming from the inlet must pass in theform of opposed jets to collide, head-on within the groove defined bythe rib, said rib groove opening toward the outlet, and a fluidcontrolling bafi'le member disposed at the mouth of said rib groove andoperative to divert the fluid issuing from said rib groove laterallywithin the muflle chamber, said bafile member comprising a disk attachedto said control baflie on the downstream side thereof.

3. In a mufller structure including means defining a muffle chamberhaving inlet and outlet ends and a plurality of baflles transverselyacross the muflle chamber,

bafi e having a ridge that is associated with the mouth 8 of the ribgroove channel of said next adjecent bathe to control flow of the fluidtherefrom. v

4. In a mufller construction including means defining a muffle chamberhaving an inlet and an outlet and a baflle across the mufiie chamberprovided witha plurality of concentric ring ribs therein projectingtoward the inlet and each having a series of orifices in the oppositewalls thereof through which fluid passing from the inlet toward theoutlet is sub-divided into a plurality of jet streams that collidehead-on within the chambers defined by the respective ribs, the ribchambers opening toward the outlet.

5. In a muffler construction including means defining a muflle chamberhaving an inlet and an outlet and a baffle across the muflie chamberprovided with a plurality of concentric ring ribs therein projectingtoward the inlet and each having a series of orifices in the oppositewalls thereof through which fluid passing from the inlet towardtheoutlet is sub-divided into a plurality of jet streams that collidehead-on within the chambers defined by the respective ribs, the ribchambers opening toward the outlet, and means extending generally acrossthe openings from the ring rib chambers for deflecting the fluid issuingtherefrom laterally within the muflle chamber.

6. In a muffler structure, a plurality of coaxially aligned andconnected sections providing fluid controlling muffling baflles within amuffle chamber defined by the sections in assembly, each of saidsections having a tubular terminal portion of substantial length andenlarged diameter providing a spaced dead air insulating and heatdissipating skirt disposed to project axially about the next adjacent ofthe sections and externally of the muflle chamber.

7. In a mufiler structure including means defining a muflle chamberhaving an inlet at one end and an outlet at the opposite end, saidchamber having fixedly thereacross and in spaced relation a plurality ofbaffle walls defining therebetween expansion spaces, each of said wallshaving a corrugation-like rib projecting generally toward the inlet endand in each instance defining anarrow channel opening toward the outletend, said ribs being defined by confronting walls, said walls havingrespective jet-forming series of orifices therein generally aligned withthe jet orifices of the confronting wall in each instance so that fluidto be muffled entering the chamber through the inlet end is forced topass through said jet orifices and provides jets of the fluid whichcollide headon with the jets from the respective opposed orifices withinthe respective rib channels before moving out of said channels into theexpansion space into which the channel opens, the height of the ribsbeing such that the crests of the ribs on the baflle walls downstreamproject closely toward the openings from the rib channels of theimmediately adjacent upstream bafile wall to thereby serve as deflectorsforcing the fluid issuing from the channels to move laterally towardeach side of the ribs thus serving as deflectors.

8. In a muffler structure including means defining a muflle chamberhaving an inlet at one end and an outlet at the opposite end, saidchamber having fixedly there across and in spaced relation a pluralityof baflle Walls defining therebetween expansion spaces, each of saidwalls having a corrugation-like rib projecting generally,

toward the inlet end and in each instance defining a narrow channelopening toward the outlet end, said ribs being defined by confrontingwalls, said walls having respective jet-forming series of orificestherein generally aligned with the jet orifices of the confronting wallin each instance so that fluid to be muffled entering the chamberthrough the inlet end is forced to pass through said jet orifices andprovides jets of the fluid which collide head-on with the jets from therespective opposed orifices within the respective rib channels beforemoving out of said channels into the expansion space into which thechannel opens, the baflle walls having attached theredefiningtherebetween expansion spaces, each of said walls having acorrugation-like rib projecting generally toward the inlet end and ineach instance defining a narrow channel opening toward the outlet end,said ribs being defined by confronting walls, said Walls havingrespective jet-forming series of orifices therein generally aligned withthe jet orifices of the confronting wall in each instance so that fluidto be muflied entering the chamber through the inlet end is forced topass through said jet orifices and provides jets of the fluid whichcollide head-on with the jets from the respective opposed orificeswithin the respective rib channels before moving out of said channelsinto the expansion space into which the channel opens, the baffle wallshaving attached thereto on the downstream side thereof respectiveauxiliary diversionary baflie plate disks extending obliquely adjacentto the openings from the rib channels of the baflle Walls to.

which attached for diverting the fluid issuing from the channelslaterally within the respective expansion chambers, said baffle platedisks being attached to the outer margins of the baflie walls and havingcentral apertures toward which the baflle plate disks are obliquelyinclined.

10. In a muflier structure including means defining a muflie chamberhaving an inlet at one end and an outlet at the opposite end, saidchamber having fixedly thereacross and in spaced relation a plurality ofbafiie walls defining therebetween expansion spaces, each of said wallshaving a corrugation-like rib projecting generally toward the. inlet endand in each instance defining a narrow channel opening toward the outletend, said ribs being i so that fluid to be mufiied entering the chamberthrough the inlet end is forced to pass through said jet orifices andprovides jets of the fluid which collide head-on with the jets from therespective opposed orifices within the respective rib channels beforemoving out of said channels into the expansion space into which thechannel opens, the baffle walls having attached thereto on thedownstream side thereof respective auxiliary diversionary bafile platedisks extending obliquely adjacent to the openings from the rib channelsof the baflle walls to which attached for diverting the fluid issuingfrom the channels laterally within the respective expansion chambers,said baffle plate disks being attached to the central portions of thebaflle walls and having outer marginal portions which are obliquelyinclined toward the perimeter of the muffle chamber.

References Cited in the file of this patent UNITED STATES PATENTS779,024 Buchner et a1 Jan. 3, 1905 1,087,397 Persson Feb. 17, 19141,607,146 Bauroth Nov. 16, 1926 1,671,829 Ledwinka May 29, 19281,741,078 Scarritt Dec. 24, 1929 2,084,435 Deremer June 22, 19372,151,084 Deremer Mar. 21, 1939 2,360,429 Leadbetter Oct. 17, 19442,576,522 Kyifin Nov. 27, 1951 2,761,525 Moss Sept. 4, 1956 FOREIGNPATENTS 9,335 Great Britain 1911 282,875 Great Britain Dec. 28, 1927816,639 France May 3, 1937

